1. Field of the Invention
The present invention relates to a light-emitting device using a light-emitting element, more specifically, to a light-emitting device configured to improve emission efficiency by arranging positions of a first resin and a second resin both having portions in direct contact with the light-emitting element and including a phosphor different from each other.
2. Description of the Related Art
In recent years, with development of a blue light-emitting diode (light-emitting diode is referred to hereinafter as LED) element having high emission efficiency, there is developed a display device achieving a full color display by combining a blue LED including the blue LED element, a red LED and a green LED (for reference, see Japanese Patent Application Publication No. 2004-4626). Such a display device includes color filters that receive light emitted from the red, green, and blue LED elements and a white LED, and the filters allow passage of red light, green light, and blue light.
The white LED generally used for such a display device has a structure in which the blue LED element and a yellow phosphor disposed to receive some blue light and emit yellow light are contained in one package. White light emitted from the entire package of the white LED is a color-mixing effect of blue light and yellow light.
However, when white light emitted from the white LED passes through the color filters described above, a color of light without a wavelength peak, for example, green light tends to be insufficient. Therefore, an LED that emits white light having wavelength peaks of RGB (red, green, and blue) is required, because RGB colors of light fit in wavelength ranges of light that pass through the color filters to produce RGB-color-balanced white light. Therefore, white LED that includes a blue LED element, a red phosphor and a green phosphor contained in one package is considered to be suitable for a display device (for reference, see Japanese Patent Application Publication No. 2005-311136).
However, in the aforementioned white LED, because a wavelength range of light that a phosphor converts is different from one another, depending on characteristics of the phosphor, and a red phosphor, for example, generally converts not only blue light emitted directly from the blue LED element, but also some green light already converted by the green phosphor to red light, there is a problem in color balance of light emitted from the entire package of the white LED.